Cutting press having improved means for clamping dies on the beam

ABSTRACT

A cutting press having a beam and a bed arranged for relative movement of approach and separation is provided with improved means for handling the cut product. The product handling means includes an improved separator means comprising separator elements and a plurality of independently yieldable support elements disposed above a table for receiving the cut product to urge separation of the cut product along cuts made by the press to lay the cut product on the table.

United States Patent [72] Inventor David F. Cremeld Bristol, England 21Appl. No. 682,953 [22] Filed Nov. 14, 1967 [45] Patented Sept. 8, 1970[73] Assignee USM Corporation Flemington, New Jersey a corporation ofNew Jersey [32] Priority Nov. 16, 1966 33 Great Britain [31] 51,259/66[S4] CUTTING PRESS HAVING IMPROVED MEANS FOR CLAMPING DIES ON THE BEAM 4Claims, 18 Drawing Figs.

[52] U.S. Cl 83/698 [51] Int. Cl 826d 7/26 [50] Field of Search 83/698[56] References Cited UNITED STATES PATENTS 2,984,176 5/l96l Sommeretal.... 83/698 3,027,792 4/l 962 Hohl 83/698 Primary Examiner-WilliamS. Lawson AtmrneysW. Bigelow Hall, Richard A. Wise and George C.

Fuller. Aubrey C. Brine and Vincent A. White ABSTRACT: A cutting presshaving a beam and a bed arranged for relative movement of approach andseparation is provided with improved means for die loading andunloading, for clamping dies on the beam, and for handling the cutproduct. The die clamping means is selectively operable to clamp diesfrom, or release them on, a feed table carried by the bed for quick andeasy die changes. The product handling means includes improved separatormeans and a stacking device having a vertically movable table andcontrol means operative in response to engagement of the upper surfaceof the stack with sensing means adjacent the under side of the feedtable to terminate upward movement of the table of the stacking device.

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Sheet 7 of 10 x 7 1 EDT Patented Sept. 8, 1970 Sheet .0 U U U U U fi Vflwwwg wmmw @w v QM s. 3w 4. %\.w 3w QM 5 J 3% www mum 3T Q .P 3 g x Q;a Tu Patented Sept. 8, 1970 Sheet em 3 83 R @sx QM mm N Patented Sept.8, 1970 Sheet wnm CUTTING PRESS HAVING IMPROVED MEANS FOR CLAMPING DIESON THE BEAM BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to improvements in apparatus for cutting sheetmaterial and more especially to improvements in apparatus relating toassemblies for cutting sheet material of the type disclosed in U.S.Letters Pat. No. 3,406,602, issued Oct. 22, 1968 in my name.

2. Description of the Prior Art In the aforementioned patent theae isdescribed apparatus for cutting sheet material comprising (i) a presshaving a beam and a bed which is mounted for movement towards and awayfrom the beam whereby sheet material fed therebetween is cut by cuttingmeans in the form of a cutting die mounted on the beam, (ii) a feedtable arranged to move between a retracted position, in which an outfeedportion of the table is positioned between the beam and the bed, and anadvanced position, in which an infeed portion of the table is sopositioned and the outfeed portion is beneath a rearward extension ofthe press beam, (iii) means mounted on the feed table for clamping thesheet material against the feed table when the table is moved from itsretracted to its advanced position, (iv) a clamping member which issupported on the rearward extension of the beam of the press and extendswidthwise of the feed table, this clamping member being spring urgeddownwardly to engage the sheet material on the feed table therebeneathwhereby, when the feed table is moved from its advanced to its retractedposition, to restrain the sheet material from movement with the table,and (v) a stacking device disposed beneath the rearward extension of thepress beam for receiving cut portions of the sheet material from theoutfeed portion of the feed table when the table is moved from itsadvanced to its retracted position.

The stacking device referred to above comprises a stacking table whichis movable heightwise with the press bed, in the operation of theapparatus, and also relative to the bed, upward movement of the stackingtable being arrested by engagement of the upper surface thereof, or ofthe upper surface of a stack of cut portions supported thereon, with theunder-surface of the outfeed portion of the feed table (which at thistime is in its advanced position) with a result that in successiveoperations of the apparatus the uppersu faceof the stacki ng tableforthe tipper iirface of a stack of cut portions supported thereon, isbrought to the same, or substantially the same, heightwise position toreceive a cut portion thereon when the feed table is moved from itsadvanced to its retracted position.

Furthermore, in the apparatus referred to above cutting dies are mountedon the under-surface of the beam manually, using toggle clamps to securethe die in position. If the die selected is to be used over a longperiod on a single production the time and effort on the part of theoperator required for fixing it to the beam is relatively unimportant.If however it is desired to change dies frequently, it is desirable toreduce the time required thereby to a minimum.

It is one of the various objects of the present invention to provide animproved assembly of the type referred to above wherein the pressureexerted by the stacking table against the under-surface of the feedtable upon engagement therebetween to arrest the upward movement of thestacking table is reduced or eliminated.

It is a further one of the various objects of the present invention toprovide improved apparatus for cutting cut sheet material in which diescan be changed in a less time-consuming and operator-fatiguing manner.

SUMMARY OF THE INVENTION There is herein described, to illustrate theinvention by way of example, apparatus for cutting sheet material from asupply of indefinite length, which is generally similar, except ashereinafter described to that described in the aforementioned patent,comprising a press having a stationary beam provided with a rearwardextension, and a bed movable towards and away from the beam, a feedtable arranged to move between a retracted position, in which an outfeedportion thereof is posi' tioned between the beam and the bed of thepress, and an ad vanced position, in which an infeed portion of the feedtable is positioned therebetween and an outfeed portion is positionedbeneath the rearward extension, and a stacking device disposed beneaththe rearward extension of the press beam and arranged to receive cutportions of sheet material from the feed table when the latter is movedfrom its advanced to its retracted position, a clamping member beingmounted on the feed table for clamping the sheet material to the feedtable as the table moves from its retracted to its advanced position,and sheet material being restrained from moving with the feed table asit moves from its advanced to its retracted position.

In the operation of the illustrative apparatus, sheet material to be cutis clamped on the feed table, on the infeed portion thereof, with thefeed table in its retracted position. The feed table then moves to itsadvanced position to carry the material to be out between the beam andthe bed of the press, a portion of sheet material cut during a previousoperation of the press being carried on the outfeed portion of the feedtable from between the beam and the bed to a position beneath therearward extension of the beam and above the stacking device. The bed ofthe press is then raised whereby the sheet material is cut and also astacking table of the stacking device is raised and its heightwiseposition is determined by engagement with the under-surface of the feedtable. After the cutting operation the press bed is lowered a smalldistance, e.g. one-eighth inch, to relieve the pressure applied betweenthe beam and the bed while maintaining the sheet material in frictionalengagement with the beam and die mounted thereon. The clamping member isthen released and the feed table moved to its retracted position whilethe sheet material is restrained from movement therewith, the cutportions beneath the rearward extension of the beam being thus depositedon the stacking device.

The illustrative press is further provided with means for detachablysupporting a die on the beam, said means comprising two clamping barsmounted on opposite sides of the beam of the press and mounted forlimited sliding movement along the length thereof between a loadingposition, in which a die can be brought into engagement with the beam,and a clamping position, in which the die is clamped on the beam, eachclamping bar being provided with a plurality of (viz. four) slots, oneend portion of each of which opens into the lower edge of the clampingbar to enable projections formed on a back plate of a die to besupported by the beam to pass into the slot. The die supporting meansalso comprises sensing means in the form of microswitches associatedwith the slots, tripping of the microswitches by engagement of theprojections of the die therewith being effective to cause the clampingbars to move lengthwise of the beam from loading to clamping positionsto clamp the die on the under-surface of the beam. The beam is alsoprovided with die locating means in the form of depending pins whichproject into corresponding holes formed in the back plate of the die andthus also are effective to hold the die against movement lengthwise ofthe beam.

The illustrative apparatus also comprises electrical control meanswhereby selectively, instead of a cutting operation being effected uponinitiation of a cycle of operation of the assembly, either a diesupported on the beam can be unloaded on to the feed table or a diepresented by the feed table can be loaded on to the press beam. Thus,when it is desired to unload a die, e.g. at the end of a series ofcutting operations on a length of sheet material, the unload" electricalcircuit is selected and a cycle of operation of the illustrativeapparatus initiated. The feed table moves to its advanced position andthereafter the bed is raised to bring the feed table into engagementwith the die. When the bed reaches the upper limit of its movement theclamping bars of the die supporting means are moved from their lockingto their loading position and the die is released on to the feed table.The bed and thus the feed table are then lowered and the feed table,together with the die supported thereon, is returned to its retractedposition. Similarly when it is desired to load a die on to the beam, theload circuit is selected. With the die to be loaded supported on theinfeed portion of the feed table and located thereon by suitable diepositioning means a cycle of operation is initiated and the feed tablemoves to its advanced position to carry the die beneath the press beam.The press bed is then raised together with the feed table to bring thedie into engagement with the under-surface of the beam, the projectionson the die back plate passing into the slots of the clamping bars, whichat this time are in the loading position, and there tripping themicroswitches to cause the clamping bars to move to their lockingposition to clamp the die in position. The bed and the feed table arethen lowered and the feed table is returned to its retracted position.The illustrative apparatus is also provided with means whereby, when adie is to be loaded, the clamping member mounted on the feed table forclamping sheet material thereagainst is held in its inoperative positioninstead of being returned to its clamping position when the feed tablereturns to its retracted position, as in the case in a cutting cycle ofoperation of the assembly.

The load" electrical circuit of the illustrative apparatus is soarranged that the microswitches associated with either clamping bar mustbe tripped before the bar is moved as aforesaid. Furthermore when allthe microswitches have been tripped, upward movement of the bed and thefeed table is arrested. In this way a die can be loaded regardless ofthe depth thereof and thus damage to the die during loading isprevented.

The die positioning means whereby a die is located on the feed tableprior to loading comprises a plurality of (viz. four) pegs supported onthe clamping member of the feed table and arranged to be received incorresponding apertures formed in the projections on the die base plate,the pegs being withdrawn from the apertures when the die has been loadedas the bed of the press and thus the feed table are lowered As in theapparatus described in the aforementioned patent, the stacking device ofthe illustrative assembly is arranged to cooperate with the feed table,the stacking table thereof being movable upwardly towards the feed table(after the latter has been moved to its advanced position), when the bedof the press is moved towards the beam, until the upper surface of thestacking table, or of a stack of cut portions supported thereon, engageswith the under-surface of the feed table, thereby determining in eachcycle of operation of the illustrative assembly the heightwise positionof the stacking table relative to the feed table for receiving a furthercut portion from the latter subsequently in the cycle of operation,sensing means being provided on the under-surface of the feed tablewhereby, upon engagement thereof by the upper surface of the stackingtable, or of a stack of cut portions supported thereon, further upwardmovement of the stacking table is prevented.

The stacking device of the illustrative apparatus is generally similarto the stacking-device described in the aforementioned application andcomprises a support which is mounted for heightwise movement with thebed of the press and on which the stacking table is supported forheightwise movement relative thereto. The support also carries ahydraulic cylinder on a piston rod on which is supported a sprocketarranged to engage with a chain extending between the stacking table anda fixed base portion of the press, so that as the bed of the press israised, thereby raising also the support of the stacking device and thehydraulic cylinder, the stacking table is raised relative to the supportat the same rate.

The sensing means provided on the under-surface of the feed tablecomprises a plurality of (viz. six) sensors in the form of fluid logicdevices, any one of which is responsive to engagement thereof by theupper surface of the stacking table, or of a stack of cut portionssupported thereon, to transmit a signal through an amplifier to operatea hydraulic valve which is effective to exhaust fluid from the end ofthe hydraulic cylinder remote from the sprocket to allow the sprocket,and thus also the stacking table, to move downwardly relative to thesupport during continued upward movement of the latter together with thepress bed, so that as the height of the stack of cut portions fed insuccessive cycles of operation of the assembly on to the stacking tableincreases, the heightwise position of the stacking table relative to thesupport is progressively lowered. As an alternative to merely allowingpressure fluid to exhaust from the cylinder, the hydraulic circuit maybe so arranged that in addition pressure fluid is admitted to theopposite end of the cylinder whereby positively to drive the sprocketdownwardly relative to the support.

The feed table of the illustrative apparatus comprises two support barsextending forwardly and rearwardly of the apparatus over a largeproportion of the length thereof, grooves being provided therefor in thepress bed and the bars being yieldingly supported therein onspring-urged rollers. The support bars carry a hardened steel plate,which constitutes the infeed portion of the feed table and against whichthe sheet material is cut, a synthetic material plate which constitutesthe outfeed portion of the feed table, and a further plate (made forexample of polymethyl methacrylate), which constitutes a separatormember and which cooperates with a second separator member shapedcomplementarily thereto and supported on the rearward extension of thebeam of the press to ensure that cut portions of sheet material areseparated from the supply thereof when received by the stacking device,as the feed table moves from its advanced to its retracted position asaforesaid. Because of the complementary shapes of the two separatormembers, which shapes are the same as the cut portions to be separatedthereby (and thus even the most intricate shapes are readily separable),a clean separation is achieved.

The second separator member is detachably mounted on the rearwardextension of the press beam constituted by a plurality of (viz. four)rearwardly extending arms each having a plurality of spring urgedmembers between any two adjacent ones of which a support block fixed onthe second separator member can be received, whereby the second memberis supported.

The illustrative apparatus further comprises a plurality of (viz. ten)supports for rolls constituting the supply of sheet material, the rollsbeing supported along a conveyor which is advanced step-by-step in timedrelation with the operation of the press of the assembly. Provision ismade for a lazy loop of material between the conveyor and the feed tableand electrical control means in the form of two microswitches (acting asupper and lower indicator switches for a carrier for the lazy' loop) isprovided whereby, when the illustrative assembly is in use, a cycle ofoperation thereof can only be initiated when a lazy loop is providedtherein.

The die supporting means of the illustrative apparatus is so constructedand arranged that instead of a single die, two separate dies can besupported on the beam side-by-side. Each of the two dies is providedwith a plurality of (viz. two) projections at either side of its baseplate for cooperating with two of the slots in either of the clampingbars, The die supporting means operates in a similar manner whether asingle die or two dies side-by-side are presented thereto by the feedtable.

Thus dies are readily changeable with a minimum of effort and time onthe part of the operator. Furthermore because the feed table and pressmembers used in carrying out a cutting operation are also utilized forloading and unloading operations, no additional mechanisms are employedto complicate the apparatus and render it more expensive.

in addition the feed table is no longer required to be of as robust aconstruction as that of the assembly described in the aforementionedapplication, since it no longer serves to resist the force of thestacking table (as determined by a hydraulic relief valve) but carriessensing means for controlling the movement of the stacking table.

it will of course be realized that the illustrative apparatus hereindescribed has been selected for description by way of exemplification ofthe invention and not by way of limitation thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be describedfurther in connection with the attached drawings in which:

FIG. 1 is a left elevation of apparatus including a press, feed table,conveyor and stacking device thereof embodying the present invention;

FIG. 2 is a front elevation partly in section on an enlarged scale of aportion of the apparatus of FIG. 1 and illustrating die supportingmechanism;

FIGS. 3, 4 and 5 are partial views of the die supporting mechanism;

FIG. 6 is a rear elevation with parts broken away, of the apparatus ofFIG. 1, showing the stacking device thereof; FIG. 7 is a front elevationof the illustrative apparatus, on an enlarged scale and with partsbroken away, showing the feed table, a sheet material clamping memberthereof (in a position in which it is held during retraction of the feedtable), and means on the press beam for controlling the extent ofretracting movement of the feed table;

FIG. 8 is a left elevation, with parts broken away, of parts shown inFIG. 7;

FIG. 9 is a plan view, with parts broken away, of a rear portion of theapparatus of FIG. 1;

FIG. 10 is a left elevation of said rear portion on an enlarged scaleand with parts broken away;

FIG. 11 is a partial rear elevation, partly in section, showing partsillustrated in FIG. 10;

FIG. 12 is a fragmentary view, on an enlarged scale, of a fluid logicsensing head ofthe illustrative apparatus;

FIG. 13 is a diagrammatic representation of the fluid logic, pneumaticand hydraulic circuits of the stacking device of the illustrativeapparatus;

FIG. 14 is a partial side elevation, on an enlarged scale, of theillustrative apparatus showing separator means of the illustrativeapparatus;

FIGS. 15 and iii are partial views showing said separator means atdifferent stages in a cycle ofoperation;

FIG. 17 is a partial section, on an enlarged scale, ofthe illustrativeapparatus showing one of four die locating means for use in a dieloading operation; and

FIG. 18 is a diagrammatic representation of an electrical controlcircuit ofthe illustrative apparatus.

GENERAL ARRANGEMENT Referring to FIG. 1, the illustrative apparatus,which is generally similar to the apparatus described in theabovementioned patent, is adapted for use in cutting sheet material froma supply of indefinite length. It comprises a moving bed toggle pressgenerally designated 30, a feed table generally designated 32 movableforwardly and rearwardly of the press, a conveyor generally designated34 arranged at the front of the press for feeding sheet material on thefeed table, and a stacking device generally designated 36 disposed atthe rear of the press for receiving cut portions of sheet material fromthe feed table.

Referring now also to FIGS. 25, the press 30 comprises a bed 38 movableheightwise on four pillars 40 towards and away from a beam 42 on whichis supported a die K comprising a steel backing plate 44 on which ismounted a plywood block 46 for supporting blade portions 48; ejectormembers 50 of a resilient synthetic material are provided within theareas defined by the blade portions whereby cut material is ejectedtherefrom. The beam is provided at both its front and rear sides,extending along the length thereof, with brackets 52 to which is secureda hardened ground steel plate 54 covering the whole area ofthe beam andconstituting a die engaging surface thereof. The" plate 54 is secured tothe brackets by a plurality of screws 56 which pass through the bracketsand the plate and have threaded on to depending shank portions thereofpeg members 58 which also serve to cooperate with correspondinglypositioned apertures 60 formed in the backing plate 44 of the die thusto receive the die in a predetermined relation on the press beam.

DIE SUPPORTING MEANS For supporting the die K on the press beam 42 thereis mounted for limited sliding movement on each of the brackets 52 aclamping bar 62 which has in cross-section the shape of an inverted L,slots 64 being provided in the horizontal portion of each clamping bar,through which slots screws 66 projecting upwardly from the plate 54 andbracket 52 pass, each screw being threaded into a securing block 68against which the upper face of the horizontal portion of the clampingbar abuts. Apertures 70 are provided in the brackets 52 and accommodatesprings 72 which serve to urge the clamping bars upwardly relative tothe brackets 52 against the securing blocks 68.

Resiliently mounted at the right hand end of the front side of the pressbeam is a piston and cylinder arrangement Ccl a piston rod 74 secured tothe piston of which carries a bracket 76 fixed to the clamping bar 62slidably supported on the front side of the beam. A second piston andcylinder arrangement Cc2 is similarly mounted at the left hand end ofthe rear side of the press beam and has a piston rod 78 which isconnected to the clampihg bar on the rear side of the beam through abracket 80.

Each clamping bar 62 is provided with four horizontal slots 32 eachprovided, at the end thereof remote from the piston and cylinderarrangement, with a depending portion which opens into the lower edge ofthe bar. The slots are positioned on the clamping bars to correspondwith projections 84 formed on the front and rear edges ofthe die backingplate 44 so that when a die is suitably located on the bed of the pressand the bed is moved towards the beam, the projections 84 will enter thedepending portions of the slots 82. An inclined face 82a joins the lowerface of each slot with the face, nearer to the piston and cylinderarrangement, of its depending portion.

Associated with two of the four slots of the front clamping bar 62, viz.the second and fourth from the right, are two microswitches LS6, LS7(see also FIG. 18) mounted on the clamping bar 62 and each provided witha downwardly spring urged plunger 86 which passes through an aperture 88arranged in the clamping bar above its associated slot 82 and throughapertures formed in the bracket 52 and plate 54 of the press beam, theplunger projecting below the plate 52 so as to be able to be engaged bythe backing plate 44 of a die K presented to the beam as aforesaid. Therear clamping bar 62 similarly has associated therewith twomicroswitches LS8, LS9 (see FIG. 18) each provided with plungers 86.

In a cycle of operation of the illustrative apparatus for loading a dieon to the press beam, a die K urged against the beam by the upwardmovement of the press bed first is effective to trip the microswitchesLS6, LS7, LS8, LS9, whereupon the piston and cylinder arrangements Ccl,Cc2 are operated to cause the front and rear clamping bars to move tothe left and right respectively, the inclined faces 82a engaging theprojections 84 which have entered the depending portions of said slotsand causing the die to be forced against the plate 54 under the pressureof the springs 72 urging the clamping bars 62 upwardly.

DIE LOCATING MEANS For locating a die K on the feed table 32 prior topresenting it for loading on to the press beam 42, the feed table hasmeans provided on a clamping member 90 which operates, in a cuttingoperation of the illustrative assembly, to clamp sheet material to becut against the feed table during a feeding stroke thereof. Forsupporting said means the clamping member 90, which comprises a hollowroller extending across the width of the feed table, is provided withgrooves 92 cut away in the surface thereof at localities correspondingto the positions of the projections 84 formed on the die backing plate44.

When a die is to be loaded, conveniently the operator places blocks 94in the shape of an inverted U (FIG. 17) over the clamping member 90 andlocates them in the grooves 92. The blocks 94 have rearwardly facingarms 96 which carry upstanding pins 98. The projections 84 are providedwith apertures 100 for receiving the pins 98. Thus the die K to beloaded is located relative to the clamping member 90 and is carried intothe press by the feed table. After the die K has been clamped againstthe plate 54 on the press beam as aforesaid, the press bed is loweredaway from the beam, and thus the pins 98 are withdrawn from theapertures 100, prior to the feed table returning to its initialposition.

For securing the blocks 94 against shifting during the operation of theillustrative assembly feet therefor may be provided by magnets 102.

FEED TABLE The feed table 32 is in the form of a composite membercomprising an infeed portion, in the form of a hardened steel cuttingplate 104 on which sheet material is supported during a cutting strokeof the press of the illustrative assembly, an outfeed portion, in theform of a plate 106 of synthetic material which receives cut portions ofsheet material and transfers them to the stacking device, and aseparator member, in the form of a clear plastic plate 108, which willbe referred to hereinafter. The three plates 104, 106, 108 are mountedon two support bars 110 extending fore and aft of the illustrativeassembly so as to provide a continuous surface. The bars 110 aresupported in grooves 112 formed in the press bed 38, rolls 114 beingprovided in recesses 116 formed in the grooves and projecting upwardlyinto the grooves under the pressure of springs 118, so that the feedtable is held clear of the press bed during movement fore and aft of thepress but can be urged thereagainst during an operative stroke of thepress.

Referring now also to FIGS. 7 and 8, secured to the front end portionsof the two support bars 110 is a cross plate 120 reinforced by a channelsection cross bar 122 at each end of which is mounted an end plate 124constituting a carriage on which are supported two rollers 126 whichride on rails 128 on support arms 130 secured to the front of the pressbed 38 and extending forwardly therefrom.

The rear end portion of each of the support bars 110 is provided with abracket 132 on which is carried a roller 134, the rollers 134 beingarranged to ride on rails 136 mounted on further support arms 138secured to the rear of the press bed 38 and extending rearwardlytherefrom.

Furthermore the feed table 32 is supported centrally by means of foursets of rollers 140 supported on brackets, two mounted on the front andtwo at the rear of the press bed 38.

The feed table 32 is thus supported for movement fore and aft of theillustrative assembly between an advanced position, in which the steelplate 104 lies beneath the press beam 42 and the plate 106 is disposedabove the stacking device 36, and a retracted position, in which theplate 106 lies beneath the press beam. For effecting movement of thefeed table there is provided in the press bed 38 to the right of centerthereof, a hydraulic piston and cylinder arrangement CH1 to the pistonof which is secured a forwardly extending piston rod, 144, the frontedge portion of the piston rod being fixed to a plate 146 secured to thecross bar 122 and depending therefrom.

The feed stroke of the feed table 32 is adjustable, for different sizesof workpieces to be cut from the sheet material, the maximum strokebeing determined in relation to the size of the press beam and bed.Since the advancedposition of the feed table is constant, in thatsuccessive feed strokes carry the sheet material to be cut to adetermined position relative to the press beam 42 and die K mountedthereon, the retracted position is varied according to the desiredlength of feed stroke (corresponding to the size of the die). Thepressure fluid admitted to the hydraulic piston and cylinder arrangementCH1 (FIG. 7) is controlled by a valve VH1 supported on the front of thepress bed 38. The valve is operated by means of a cam block 148 mountedin a hollow member 150 of square cross-section accommodated in a bore152 in the press bed and threadedly receiving a rearward end portion ofthe rod 154 secured at its forward end portion in the plate 146, a knob156 being provided at the forward end of the rod 154. The position ofthe cam block 148 fore and aft is thus adjustable by turning of the knob156 to vary the relative fore and aft positions of the member 150 andthe rod 154.

The member 150 passes through a square aperture 158 formed in a flangedbush 160 clamped, by means of two clamp screws 162 passing through slots164 formed in the bush to the front of the press bed for limitedrotational movement thereon. Rotation of the bush 160 is effected bymeans of a handle 166 at the left hand side of the press connected tothe disc by a link 168, rotation of the disc between a first and asecond position being effective to move the cam block 148 between anoperative position, in which during a return stroke of the feed table itengages a plunger 151 connected to the valve VH1, and an inoperativeposition.

Operation of the valve VH1 by the cam block 148 is effective not only tocause the movement of the feed table to its retracted position to bearrested but also causes the clamping member 90 to move from aninoperative position, away from the upper surface of the feed table, toan operative position. The clamping member 90 comprises, as abovestated, a hollow roller and is mounted on a rod 170 pivotally supportedat either end by arms of bell crank levers 172 in turn pivotally mountedin lugs 174 secured to the end plates 124. The other arms of the bellcrank levers 172 are pivotally connected to links 176 mounted forsliding movement transversely of the feed table in bearings 178depending from the under-surface of the cross plate 120. Mounted to theleft of center of the plate 146, depending from the cross bar 122, is apiston and cylinder arrangement CH2 a piston rod 179 secured to thepiston of which carries a cross pin 180 to opposite ends of which aresecured ends of two chains 181, each chain being secured at its otherend, to one of the links 176. Movement of the piston rod 179 downwardlyis thus effective, through the chains 181, to cause the clamping member90 to be raised to its inoperative position, springs 177 action betweenthe bearings 178 and the links 176 being effective to return the pistonrod heightwise and thus also to move the clamping member to itsoperative position. In a cutting cycle of operation of the illustrativeapparatus, the clamping member is in its operative position during afeed stroke of the feed table, i.e. during movement of the feed tablefrom its retracted to its advanced position, a hydraulic valve (notshown) being provided whereby the clamping member 90 is caused to moveto its inoperative position during a return stroke of the feed table.

When it is desired to unload or load a die, it is necessary that,regardless of the length of the feed stroke of the feed table duringprevious cutting operations, the feed table be moved to its extremeretracted, i.e. forward, position (as determined by the maximum lengthof stroke of the hydraulic piston and cylinder arrangement CH1). Inaddition if any sheet material remains to be fed to the press, it isdesirable that this should not be clamped to the feed table for the dieloading or unloading operations. Thus when it is desired to load orunload a die, the operator moves the bush 160 to its second position torender the cam block 148 inoperative so that the feed table is retractedto its extreme forward position and the clamping member 90 remains inits inoperative position.

STACKING DEVICE The stacking device 36 of the illustrative apparatuscomprises a supporting frame comprising two vertical posts 182 securedon the rearward extending support arms 138 of the press and three crossstruts 184 secured therebetween. The

posts are slidable in linear bearings 186 supported in brackets 188secured on a base portion 190 of the press. The cross struts 184 supporta hydraulic piston and cylinder arrangement Csl a piston rod 192 securedto the piston of which carries a sprocket 194. Mounted for heightwisemovement on rails 182: formed integral with the posts 182 are tworearwardly extending arms 196 connected to one another by cross rods 198to form a stacking table, each arm 196 having secured at its front end aplate 200 on which are carried four rollers 202, the arrangement beingsuch that two rollers run at either side of the rail 182s. A chain 204is secured, at one end, to one of the cross rods 198 of the stackingtable and, at the other, to the base portion 190 of the press. Thusupward movement of the press bed 38 is effective to raise the supportingframe of the stacking device 36 therewith and is also effective, throughthe sprocket 194 and chain 204, to cause the stacking table to be raisedrelative to the supporting frame, the arrangement being such that thedistance moved by the stacking table is in a 2:1 ratio with the distancemoved by the press bed.

Upward movement of the stacking table is limited by engagement of theupper surface of a pallet P or stack S of cut portions carried therebywith the under-surface of the plate 106 of the feed table 32, which isin its advanced position when the press bed is caused to rise. Forcontrolling the movement of the stacking table there is provided, as maybe seen in FIG. 9, in recesses formed in the under-surface of the plate106 six fluid logic sensing devices generally designated 206.

Each sensing device 206 comprises a block 208 (FIG. 12) of,

synthetic material having an inlet bore 210 and an outlet bore 212 bothof which open into a chamber 214 which is open to atmosphere through anaperture 216. The inlet bores 210 of the six devices are connected bysmall diameter pipes 218 to a manifold block 220 mounted on theunder-surface of the plate 106 towards the rearward end thereof. Airunder pressure is supplied to the manifold block 220 through a rigidpipe 222 which depends from the block and is connected through a recoilpipe 224 with an air source piped to a housing 225 for the fluid logicsystem of the illustrative assembly mounted on the rear of the press bed38. The outlet bores 212 of the six devices are connected to smalldiameter pipes 226 which pass together inside a rigid large diameterpipe 228 depending from the plate 106 and inside a large diameter recoilpipe 230. The pipes 226 are connected to a turbulence amplifierarrangement TA (shown schematically in FIG. 13) as a single turbulenceamplifier and therethrough to a step up transformer SUT which controls avalve Vsl in the pneumatic circuit of the stacking device 36.

Referring now to FIG. 13, air under pressure is admitted through pipesPs1, Ps2 to the valve Vsl and to a manually operable valve Vs2respectively. When the illustrative assembly is at rest air will not beallowed to pass through either valve. When, however, the upper surfaceof a pallet P or stack S of cut portions is raised into engagement withthe plate 106, the apertures 216 of the sensing devices are closed andthus a signal, in the form of an air pulse returned now along the outletpipe 212, is transmitted to the turbulence amplifier TA, therebyupsetting the signal passing to the step up transformer SUT when theassembly is at rest. When no signal is transmitted to the transformerSUT the valve Vsl is opened to admit air under pressure to pipes Ps3,Ps4 thereby operating respectively three way valve V53, to shift it tothe right viewing FIG. 13, and valve Vs4, to shift it to the leftviewing FIG. 12. Operation of valve Vs4 in this manner exhausts pipePs5, connected to the opposite (right hand, viewing FIG. 13) side of thevalve Vs3, to atmosphere. The valve Vs4 is normally spring urged to theright, thus to connect pipe PsS, through pipe Ps6, with the manuallyoperable valve V32.

Movement of the valve Vs3 to the right as aforesaid allows hydraulicfluid to be pumped to the upper side of the piston and cylinderarrangement Crl thereby causing the piston, and thus the sprocket 194carried by the piston rod 192, to be lowered. The valve V53 isself-centering so that when the signal to the step up transformer SUT isagain applied and admission of air under pressure through the valve Vslis prevented, the valve Vs3 assumes the position shown in FIG. 13, inwhich hydraulic fluid is admitted to neither side of the piston.

When the stack S of cut portions is full it is removed and thereafterthe stacking table can be raised to its upper limit by operating themanually operable valve Vs2, air under pressure being then admittedthrough pipe Ps6, valve Vs4, and pipe Ps5 to the right hand side(viewing FIG. 13) of the valve Vs3 to shift it to the left. Hydraulicfluid is then admitted to the underside of the piston of the arrangementCsl to raise the piston rod 192 and sprocket I94, thereby, through thechain 204, raising the stacking table also.

The fluid logic system is so arranged that a signal from any one of thesensing devices 206 is effective to cause no signal to be transmitted tothe transformer SUT.

In case it is desired to cause the stacking table to be lowered, amanually operable valve Vs7 is arranged in the fluid logic system,actuation thereof being effective to transmit a signal to the turbulenceamplifier TA in the same manner as the sensing devices 206.

SEPARATOR MEANS The beam 42 of the illustrative press is provided with arearward extension in the form of four rearwardly extending support arms232 (two only shown in FIG. 9) carried on the rear side of the pressbeam and supported by stays 234 thereon. The four arms are of the sameconstruction and one only will now be described.

Each arm 232 has in cross-section the shape of an inverted U andreceives therein eleven support elements 236 of hollow section mountedin the arm 232 end to end. Associated with each element 236 the arm 232has a boss 238 extending up wardly from the top of the arm for receivinga headed pin 240 the shank of which passes into the element 236 andabuts, at its lower end, against the inner surface of the bottom of theelement. A countersunk screw 242 passes through an aperture in thebottom of the element and is threadedly received in a bore formed in thelower end portion of the pin shank so that the element is clampedbetween the lower end of the shank and the countersunk head of thescrew. A spring 244 cmbraces the pin shank and acts between an innerface of the top of the 232 and the inner face of the bottom of theelement 236 to urge the element downwardly relative to the arm. Also,associated with each element 236, a guide pin 246 is secured to theinner surface ofthe top ofthe arm 232 and projectirig downwardly to bereceived in a sleeve 248 mounted in the element 236. Thus the elements236 are yieldingly mounted, independently of one another, in the arms232.

The arms 232 are arranged to support a separator member 250 having aseparating edge 250a (FIGS. 15 and 16) shaped complementarily to theshape of the edge of the cut portion to be separated thereby and also tothe shape of the separating edge 1080 of the plate 108 (forming part ofthe feed table) with which the member 250 cooperates.

In order to enable the member 250 to be supported on the arms 232, it isprovided with four hooks 252 secured on the upper surface thereof, eachhook comprising an upright portion and a securing portion extendingforwardly from the upright portion. The securing portion is receivedwithin one of the hollow section elements 236, a portion of the end,remote from the press beam, of the bottom of each element being cut awayto receive the upright portion of the hook. In mounting a separatormember 250 on the arms, conveniently the operator places it slightly tothe left (viewing FIG. 1) of the position in which it is desired tosupport it and urges it upwardly so that the hooks 252 press against theelements 236 adjacent those on to which it is desired to hook the memberthus causing them to retract against the pressure of the springs 244.When the upper surface of the member 250 engages the elements the memberis then moved to the right (see FIG. 1) to cause the lower surfaces ofthe securing portions of the hooks and the upper surface of the memberto pass along opposite sides of the bottom of the elements whereby themember is secured thereto. When the member is moved sufficiently to theright the adjacent elements are caused to spring back into theirlowermost position, thereby locking the hooks 252, and thus the member250, in position.

In order that the plate 108 can be positioned accurately in relation notonly to the position of the member 250 but also to the length of thefeed stroke of the feed table, the position of the feed table fore andaft of the illustrative apparatus can be varied. For this purpose eachend plate 124 constituting the carriage for the forward end of the feedtable is provided with an outwardly projecting lug 254 on which a clamp256 can be secured, the arrangement being such that with the clamps 256in an inoperative condition the feed table can be moved lengthwise ofthe support bars 110 to a desired position, whereafter it is clamped inposition.

In a cycle of operation of the illustrative apparatus a cut portion ofsheet material deposited on to the plate 106 of the feed table iscarried to a position above the stacking device when the feed table ismoved to its advanced position. Thereafter the press bed and stackingtable are raised as aforesaid to the limit of approach of the beam andbed, the feed table also being raised with the press bed to urge the cutportion supported thereon against the separator member 250 which,together with the elements 236, is caused to yield upwardly against thepressure of the springs 244. After the sheet material on the steel plate104 has been cut the bed is lowered through a small distance such thatwhen the feed table is moved to its retracted position the sheetmaterial is restrained from movement therewith. As the plate 108 isdrawn forwardly each element 236 returns under spring pressure to itsinitial position and the cut portion is progressively laid on the stackS. As the plate 108 is drawn past the separator member 250 the latter isheld in its retracted position until the plate moves out of engagementtherewith, the member 250 then being urged downwardly under the springpressure and the edge thereof effecting a shear action with the edge ofthe plate 108 to insure that the cut portion is completely severed fromthe next portion of sheet material (see FIGS. 15 and 16).

CONVEYOR The conveyor 34 of the illustrative apparatus (FIG. 1)comprises an endless belt 258 which passes round drive rollers 260 (oneonly shown in FIG. I) mounted in a frame 262 inclined at an angle of 30to the horizontal. Mounted along the frame, at each side thereof, areten supports 264 (one only shown in FIG. 1), the supports being thusarranged in pairs of supporting rolls R of sheet material to be cut.

The frame 260 of the conveyor is supported at its rearward ends by twosupport structures 266 having in side view an H arrangement. Therearward ones of the uprights of these structures are longer than theforward ones and support between the upper ends thereof a roll of paperRb which is fed into the press with the sheet material. Thus, a layofsheet material to be cut comprises ten layers of sheet material (e.g.cloth) and a layer of paper, whereby when the portions have been cut andstacked a layer of paper is interspersed between each ten cut portionsofsheet material.

Also supported in the structures 266, for heightwise movement therein,is a roller 268 supported at its ends by blocks 270 slidable in channels272 formed in the structures, the arrangement being such that the tenlayers of sheet material pass round the roller 268 to the feed tablethus forming a lazy loop in the material. The forward ends of thesupport bars 110 carry a roller 274 to facilitate feeding of thematerial from the lazy loop. When the roller 268 is in its lowermostposition one of the blocks 270 trips a microswitch L514 mounted on theside of one of the channels. This switch has a normally closed partLS14a and a normally open part LSl4b. At the start of a cycle ofoperation the feed table moves towards its advanced position and drawsthe material of the lazy loop thereby raising the blocks 270 andreleasing the microswitch L514. The normally closed part LS14a isarranged in a conveyor motor M3 circuit and release thereof closes thecircuit to cause the conveyor to be driven. Operation of this motor isarrested when the microswitch is again tripped.

Should it be that the conveyor does not operate as aforesaid uponmovement of the feed table, the lazy loop roller 268 is carried to thetop of the channels 272 and there trips a normally closed upper limitswitch LS16 also mounted on the side of one of the channels 272, whichswitch breaks the circuit to the feed table, the latter being thusreturned to its retracted position.

OPERATION: CUTTING (SINGLE STROKE) When it is desired to operate theillustrative apparatus on single stroke cutting, the operator sets aselector switch Sla, $112,510 to a position designated 1 in FIG. 18.

.He then presses a normally open start switch P124 comprising two partsPb4a, Pb4b. In single stroke cutting, part Pb4a is rendered inoperative.Closing part Pb4b of the start switch is effective, through a limitswitch LS3 and a contact RL2b both normally in their positions shown inFIG. 18, the normally closed limit switch L516, the part LS14b of thelazy loop lower limit switch held closed by one of the blocks 270, and afurther normally closed limit switch LS15 (which is tripped to open whenthe stacking device has a full stack S of cut portions thereon), to makea circuit to a relay RLla and a solenoid SOL3 which is effective tocause the feed table 32 to move to its advanced position. Energizationof relay RLl closes normally open contacts RLla, RLlb thereby bypassingrespectively the limit switches LSl4b, L515, and the start switch Pb4b,which latter can then be released. Since the limit switch LS14b isbypassed movement of the feed table is not arrested when it opens uponthe lazy loop roller 268 being raised.

When the feed table has almost reached its advanced position, a normallyopen limit switch LS1 is momentarily tripped, thereby making a circuitto a relay RL3 and energizing two solenoids SOL10,SOL11 which operate abatch counter and a total counter respectively. Energization of therelay RL3 causes contacts RL3a, RL3b to move from their positions shownin FIG. 18 whereby a holding circuit to the relay RL3 is made throughthe contact RL3a, the selector switch Sla and a normally closed pressbed upper limit switch LS5. When thereafter the feed table reaches itsadvanced position a normally open limit switch LS2 is closed which makesa circuit to a solenoid SOLl effective to cause the press bed to beraised. Raising of the press bed is effective to allow a press bed lowerlimit switch LS4 to move from its positions shown in FIG. 18.

When the press bed reaches the upper limit of its movement the normallyclosed switch LS5 is opened thereby de-energizing the solenoid SOLl,thus preventing further upward movement of the bed, and the relay RL3,thus causing the contacts RL3a, RL3b to return to their positions shownin FIG. 18. A circuit is then made, through the limit switch LS3normally held in the position shown in FIG. 18, the contact RL3a, limitswitch LS4 and selector switch Slb, to the solenoid SOL2 wherebylowering movement of the press bed is initiated.

When the press bed has been lowered through a small distance such thatthe sheet material is still held in frictional engagement with the die Kmounted on the press beam, the limit switch LS3 is tripped and movesfrom its position shown in FIG. [8 to break the circuit to the solenoidSOL2, to arrest the downward movement of the press bed. and make acircuit to a timer device TMR, which is set to allow a dwell period insaid downward movement. In addition the movement of the limit switch asaforesaid breaks the circuit held through the contact RLlb, limit switchLS16 and contact RLla to the relay RLl and to the solenoid SOL3 thusde-energizing them whereby the feed table is caused to be returned toits retracted position. Movement of the feed table is arrested byengagement of ,the cam block 148 with the valve VH1, which is effectiveto prevent further admission of hydraulic fluid to the piston andcylinder arrangement CH1 which drives the feed table and also to exhausthydraulic fluid from the piston and cylinder arrangement CH2 to allowthe clamping member 90 to clamp the sheet material on to the feed tableunder the influence of the springs 177. The timer TMR is so set that thefeed table is returned and the sheet material clamped as aforesaidbefore any further movement of the press bed is effected.

When the dwell period controlled by the timer TMR is completed, anormally open timer switch TMRl is closed thereby again making thecircuit to the solenoid SOL2 and thus causing the downward movement ofthe press bed to be continued. The switch LS3 is thereupon returned toits position shown in FIG. 18. When the press bed reaches the lowerlimit of its movement, the limit switch LS4 is returned to its positionshown in FIG. 18 and the circuit to the solenoid SOL2 is broken.

The cycle of operation of the illustrative apparatus is then completed.It will of course be understood that the stacking table of the stackingdevice moves with the press bed in the manner described above and a cutportion of sheet material is deposited on the stack 3 of cut portionswhen the feed table is retracted, as above described.

OPERATION AND CUTTING (AUTOMATIC) When it is desired to operate theillustrative apparatus in an automatic cutting mode, the operator setsthe selector switch Sla, Slb, Sllc to a position designated 2 in FIG.18. He also conveniently sets the batch counter to the number of cutsdesired.

The operator starts the operation of the illustrative assembly in thesame manner as for single cutting, viz. by pressing the start switch PM.The operation of the operation ofthe assembly then takes place in thesame manner as for single cutting except as follows:

Pressing the start switch Pb4a makes a circuit through the selectorswitch 51c with a relay RL4 and also a lamp LP3 to indicate thatautomatic cutting is selected. Energization ofthe relay RL4 causesnormally open contacts RL4a, RL4b to be closed; a holding circuitthrough the contact RL4a is thus made to the relay RL4 bypassing thestart switch. This holding circuit is maintained throughout the whole ofthe automatic cutting operation. In addition, when the lower limitswitch LS4 is moved to its position shown in FIG. 18 at the end of eachcutting stroke, it makes, through the limit switch LS3, contact RL3a,contact RL4b (held closed by the relay RL4), a batch counter operatedswitch B510 normally held in its position shown in FIG. 18, and limitswitches L516, LS14b and L515, a circuit to the solenoid SOL3 whereby anew cutting cycle of operation is initiated.

Each time that the switch LS1 is tripped, as the feed table is moved toits advanced position, a pulse is transmitted to the batch counter. Whenthe number of pulses equals the pre-set number the switch B510 is movedfrom its position shown in FIG. 18 thereby breaking the circuit to thesolenoid SOL3 and bringing the automatic cutting operation to an end. Inaddition it rnakes a circuit to a lamp LP2 to indicate that theoperation is ended.

OPERATION: DIE UN LOADING When it is desired to operate the illustrativeapparatus to unload the die It from the press beam, the operator setsthe selector switch Sla, Slb, 51C to a position designated 3 in FIG.

The operator again initiates an unloading cycle of operation in the samemanner as for single cutting arid the cycle of operation continues in agenerally similar manner to a single cutting operation until the pressbed reaches its upper limit, opening the limit switch LS and thuscausing the relay RL3 to be de-energized. When the contact RL3a nowreturns to its position shown in FIG. 18 a circuit is made, through thelimit switch LS3, said contact RL3a, the limit switch LS4 (which hasbeen moved from its position shown in FIG. 18) and the selector switchSlb. to a relay RL2 and also to a solenoid SOLS effective to cause thefront and rear clamping bars 62 to move to the right and left (viewingFIG. 2) respectively, thus to release the die K on to the press bed.Movement of the piston rod 74 of the piston and cylinder arrangement C01associated with the front clamping bar 62 is also effective to allow anormally closed part LS17a of a switch LS17 mounted on the press beam toclose and a normally open part LS17b thereof to open and to allow afurther switch L510 mounted adjacent the switch L517 on the press beamto move from its position shown in FIG. 18 whereby a circuit is made tothe solenoid SOLZ to initiate the downward movement of the press bed.When the die moves away from the clamping bars 62, the switches LS6,LS7, LS8, LS9 move to their positions shown in FIG. 18.

Energization of the relay RL2 is also effective to cause a normally opencontact RLZa to close and the contact RL2b to move from its positionshown in FIG. 18. Thus when the press bed is moved downwardly, thetripping of the switch LS3 is rendered ineffective since a circuit ismade through the contact RL2b, contact RL3a, switch LS4 (which has beenmoved from its position shown in FIG. 18), selector switch S112, andswitches LS17a and L510 to the solenoid SOL2 whereby the press bed ismoved continuously downwardly. Movement of the contact RL2b from itsposition shown in FIG. 18 breaks the circuit to the solenoid SOL3 but analternative circuit is made through the contacts RL2b and RL3a, theswitch LS4 and the contact RLZa. When the press bed reaches its lowerlimit and thus returns the switch LS4 to its position shown in FIG. 18said alternative circuit is broken, whereby the feed table is thencaused to return to its retracted position, and the relay RL2 isde-energized thus returning the contacts RLZa, RL2b to their positionsshown in FIG. 18.

OPERATION: DIE LOADING When it is desired to load a die K on to thepress beam, the operator sets the selector switch Sla, Slb, Slc to aposition designated 4 in FIG. 18.

With the die K to be loaded supported on the feed table and locatedthereon by means of the blocks 94, the operator presses the start switchPM!) and. as with a single cutting operation, the feed table moves toits advanced position and thereafter the press bed is raised. As the dieK is moved against the press beam the backing plate 44 thereof engageswith the switches LS6, LS7, LS8, LS9 closing the normally open partsLS6a, L57a, LS8a, L590 whereby a circuit is made to a solenoid SOL6effective to cause the front and rear clamping bars 62 to be moved tothe left and right respectively to clamp the die on the press beam. Atthe same time normally closed parts LS6b, LS7b, LS8b, LS9b of theswitches are opened thereby breaking the circuit to the solenoid SOLI,thus preventing further upward movement of the press bed andde-energizing the relay RL3; in this way any possible damage to the dieis avoided. Also at the same time the switches L510, LS17a, and LSl7bare returned to their positions shown in FIG. 18 thereby making acircuit to the solenoid SOL2 which is effective to cause the press bedto move downwardly again.

The remainder of the cycle of operation is then effected in the samemanner as for single cutting, the bed first being lowered sufficientlyto ensure that the pins 98 of the blocks 94 are first withdrawn from theapertures 100 of the projections 84 on the die.

It will thus be noted that with the illustrative apparatus, dies can beloaded and unloaded using only the parts of the apparatus which areprovided for the cutting operation thereof. Furthermore the stackingdevice of the apparatus operates without applying undue stress to thefeed table which may consequently be made of a lighter material thanwould otherwise be the case.

As an alternative to loading a single die which covers the whole of thearea of the base, the separate dies (not shown) may be mounted side byside on the beam without affecting in any way the operation of the pressdescribed above.

I claim:

1. Apparatus for cutting sheet material comprising in combination apress having a beam and a bed mounted for relative movement of approachand separation, die supporting means carried by said beam and operableselectively for clamping thereon a die presented thereto in apredetermined relative disposition and/or for unclamping a die supportedthereby and a sensing means associated with said die supporting meansand operative upon engagement of a die therewith to cause the clampingmeans of said die supporting means to be actuated to clamp the die onsaid beam.

2. Apparatus for cutting sheet material comprising in combination apress having a beam and a bed mounted for relative movement of approachand separation, die supporting means carried by said beam and operableselectively for clamping thereon a die presented thereto in apredetermined relative disposition and/or for unclamping a die supportedthereby, a feed table movable between an advanced position in which aportion of the feed table is positioned between the beam and the bed ofthe press, and a retracted position in which a die to be detachablysecured to the beam of the press can be placed on said portion of thefeed table, said feed table having means thereon for locating a diethereon in a predetermined disposition when the feed table is in itsretracted position, whereby when the feed table is caused to move to itsadvanced position to carry the die between the beam and the bed of thepress, and a relative movement of approach is effected between the beamand the bed of the press to cause the die and the beam to be broughtinto engagement with one another, the die is in said predeterminedrelative disposition whereby the die supporting means is operative forclamping the die onto the beam.

3. Apparatus as in claim 2 and additionally comprising die sensing meanscarried by the die supporting means and operative in response toengagement of a die therewith to cause clamping means of the diesupporting means to clamp the die onto the beam.

4. Apparatus as in claim 3 in which said die sensing means isadditionally operative in response to engagement of a die therewith toterminate relative movement of approach of said beam and bed.

